Summer of 2010 was the 4th Warmest on Record.

04/10/2010 17:12

Global surface temperatures in the Northern Hemisphere summer of 2010 were slightly below 2009, but NASA's Goddard Institute for Space Studies reports that the season was still the 4th warmest in 131 years of records.

Regional differences were naturally variable, but GISS Director James Hansen said the global differences from last year to this were the result of changing ocean conditions in the Tropics. "2010 was a bit cooler than 2009 mainly because a moderate El Nino in the equatorial Pacific Ocean during late 2009 and early 2010 has been replaced by a moderate La Nina," he said.

Goddard released this set of maps comparing "seasonal mean temperature anomalies" for the last two winters (left) and summers (right). In the lower right panel, notice the striking differences between temperatures in the eastern and western U.S., and the enormous, lethal heatwave signature in Eastern Europe and Russia.

"These maps make clear that perceptions of how hot it was depend on where you live," observed Hansen.

Here's how Hansen described the lower right panel of global temperatures during the Northern Hemisphere summer months of June through August:

The two warmest anomalies on the planet this past summer were Eastern Europe and the Antarctic Peninsula. Not many people live on the Antarctic Peninsula and an anomaly of even several degrees in winter there is not a big deal. But the warm anomaly centered in Eastern Europe, which covered most of Europe and the Middle East, was noticed, to say the least.

It was also quite warm in Japan, where the prior summer had been cooler than the 1951-1980 mean. The United States, which had been unusually cool in the summer of 2009, was warm this past summer, except the Pacific Northwest, which was cooler than the 1951-1980 climatology.

Hansen said the maps "may help people understand that the temperature anomaly in one place in one season has limited relevance to global trends."